​Epidemiology:
Incidence of Disease:
The annual incidence in the US is approximately 1 case per 100,000 people.
Biliary tract cancer is more common in Israel and Japan and in American Indians than in the general US population.
Patients are typically elderly, average age 60-65 years with a very slight male preponderance.²

Etiology:
​The risk factors for biliary tract cancer include the following:
•family history of congenital fibrosis or cysts
•parasitic infestations
•gallstones and hepatolithiasis
•primary sclereosing cholangitis
•ulcerative colitis either with or without coexisting PSC
•toxic materials (thorium dioxide, radionuclides, arsenic, dioxin, nitrosamines, polychlorinated biphenyls)
•drugs (oral contraceptives, methyldopa, isoniazid)
•chronic typhoid carriers
•biliary cirrhosis.²

Signs & Symptoms
​Patients often present with painless, obstructive jaundice, weight loss or Courvoisier's gallbladder (papable). Peritonea seeding at initial presentation was reporting in 19%-20% of cases.¹
Diagnostic Procedures:
Workup studies to include:
•liver function tests
•complete blood picture
•levels of serum CEA
•serum mitochondrial antibody test²
•imaging studies to include Ultrasound, CT and thin needle percutaneous biopsy with a transhepatic catheter in position.¹

Histology:
More than 95% of bile duct cancers are of the adenocarcinoma type. One of the most common causes of extrahepatic biliary obstruction is choledocholithiasis, with one or more stones in the common bile duct or common hepatic duct causing biliary obstruction. Cholangiocarcinoma is an adenocarcinoma of the bile ducts.¹
Lymph Node Drainage:
Primary lymphatic drainage is to nodes within the porta hepatis and pancreaticoduodenal groups.¹
Metastatic Spread:
Metastases to the liver is most common, followed by distant spread to the peritoneum and lung. Mets to the ovaries, spleen, bone, and other distant organs is possible, but less common.¹
Grading:
Grade should be reported based on the following:

GX Grade cannot be assessed
G1 Well differentiated
G2 Moderatley differentiated
G3 Poorly differentiated
G4 Undifferentiated⁴

Staging:
AJCC/TNM (see table below)¹
Biliary_Tract_Staging.jpg

Radiation Side Effects:
With external irradiation doses of 55 Gy or less to the duodenum or stomach, the risk of severe gastrointestinal complications varied from 5% to 10%. At doses greater than 55Gy, one-third of patients developed severe problems. In patients who received external irradiation plus iridium, the dose to the external field was limited to 50.4 Gy, but most received additional irradiation dose to the duidenum or stomach from the iridium boost. There was a 30% to 40% incidence of severe complications in the duodenum or stomach in this group of patients.

Transhepatic catheters were previously left in place in these patients until the degree of stenosis stabilized or lessened on serial cholangiograms, which usually occurred within 12 to 18 months of treatment. Because of stent-related morbidity, attempts are now made to remove transhepatic catheters or endoscopic stents within 3 to 6 months of the brachytherapy boost, if imaging techniques of the biliary tree suggest this is mediclaly feasible.¹

Prognosis:
The prognosis and treatment options depend on the following, but usually the prognosis is not good.
The stage of the cancer (whether it affects only the bile duct or has spread to other places in the body).
Whether the tumor can be completely removed by surgery.
Whether the tumor is in the upper or lower part of the duct.
Whether the cancer has just been diagnosed or has recurred.³

Treatments:
General Management
  • Usual options include surgical bypass, U-tubes, or nonoperative decompression with percutaneous transhepatic catherters or a retrograde endoscopic prosthese.
  • Surgical removal of a malignant gallbladder lesion often necessitates blunt dissection from the liver with narrow or nonexistent margins.
  • Lesions in the periampullary region or distal common duct carry a uniformly better prognosis; resection with a Whipple procedure is usually feasible and yields long-term survival in 30% tpo 40% of these patients.
  • Single chemotherapeutic agents capable of invoking tumor response include 5-FU and mitomycin-C.
Radiation Therapy Techniques
  • Although the superior and inferior extent of disease can often be outlined by a percutaneous cholangiogram, the amount of extraductal disease is poorly defined by any noninvasive procedure.
  • Clip placement at surgical exploration or resection can be useful in outlining the extrahepatic portion of ductal lesions and defining the bed of the gallbladder.
  • Areas at risk for local relapse include the tumor bed, unresected tumor and nodes along the porta hepatis, pancreaticoduodenal system, and celiac axis.
  • The simulation procedure is similar to that for pancreatic cancer.
  • The initial large-field treatment volume can be included to 40 to 45 Gy in 1.7 to 1.8 Gy fractions with a three or four field plan. If possible, blocks are used to exlude normal stomach, small intestine, kidney, and liver.
  • Use of lateral fields for part of the treatment allows decreased dose to the spinal cord, right kidney, and portions of the liver.
  • Wedge pair techniques can be used in large or boost fields to alter dose distribution.
  • Liver tolerance to irradiation may necessitate an initial field reduction after 30 to 36 Gy and, if gross disease exists, a second reduction after 45 to 50 Gy.
  • For bile duct primary lesions, the preferred intrahepatic field margin beyond gross ductal disease is 3 to 5 cm because of the tendency for submucosal spread within lymphatics; these margins may need to be reduced to 2 to 3 cm after 30 to 36 Gy.
  • The upper dose level within the second boost is 55 to 70 Gy, delivered over 6.5 to 8 weeks with external beam alone.
  • If boost-dose irradiation is feasible with brachytherapy techniques, the tumor nodal dose is carried to 45 to 50 Gy with external techniques, and 20 to 30 Gy is delivered to a 1-cm radius with transcatheter iridium 192.
  • Significant palliation (and occasional long-term survival) can be obtained with external-beam irradiation of unresectable or recurrent ductal lesions to doses of 40 to 70 Gy given in 4.5 to 8 weeks; however, permanent local control is uncommon.¹
TD5/5:
Dose to the following organs should be considered:

Liver -- the whole liver can receive 20 to 30 Gy, with an upper threshold of 33 to 35 Gy. One-third to one-half of the liver volume can receive more than 40 Gy without complications.
Kidney -- 1/3 can receive 50 Gy, 2/3 can receive 30 Gy, the whole kidney can receive 23 Gy.
Spinal cord -- 45 Gy
Stomach -- 1/3 can receive up to 60 Gy, 2/3 is 55 Gy, and the whole stomach tolerance is 50 Gy
Small intestine -- 1/3 to 50 Gy and all to 40 Gy¹

Planning Photos:
Treatment planning for a bile duct mass. This is a 5-field 3D treatment plan to a dose of 4500 cGy in 25 fractions. The patient will also receive a 900 cGy boost in 5 fractions.5
Bile_Duct.JPG
References
1. Chao KS, Perez CA, Brady LW. Radiation Oncology - Management Decisions, 2nd ed: 383-394. Philadelphia, PA: Lippincott, Williams & Wilkins, 2002.
2. eMedicine. Bile Duct Tumors. http://emedicine.medscape.com/article/189843-overview. Accessed January 18, 2010.
3. Cleveland Clinic. http://my.clevelandclinic.org/disorders/extrahepaticbileductcancer/hicextrahepatic
bil. Accessed January 21, 2010.
4. AJCC Cancer Staging Manual. 7th ed. New York, NY: Springer; 2010: 214, 229, 235.
5. Courtesy of Sherilee Griffin. Samaritan Regional Cancer Center. Corvallis, OR.

Ginnie is bright blue.
Bridget is green.
Sheri is brown.
Zack is purple.